Biological Beginnings

Biological Beginnings The Evolutionary Perspective Genetic Foundations of Development Heredity and Environment interaction: The Nature-Nurture Debate Prenatal Development Birth

The Evolutionary Perspective The Evolutionary Perspective • Natural selection and adaptive behavior • Darwin and his observations • All organisms must adapt in life • Evolutionary psychology • Emphasizes adaptation, reproduction, and survival of the fittest in shaping behavior • Evolution explains human physical features and behaviors

The Evolutionary Perspective Evolutionary Developmental Psychology • Explaining humans and their behavior • Larger brains and more complex societies • Takes longest of all mammals to mature • Some evolved mechanisms of adaptation not compatible with modern society

The Evolutionary Perspective Evolution and Life-Span Development • Benefits of evolutionary selection decrease with age • Natural selection failures: harmful conditions and non-adaptivecharacteristics • As adults weaken biologically, culture-based needs increase • Alternative: ‘bi-directional view’

The Evolutionary Perspective Baltes’ view of evolution and culture across the life span

The Evolutionary Perspective Evaluating Evolutionary Psychology • Remains just one theoretical approach. • Evolution does not dictate behavior. • Biology allows broad range of cultural possibilities.

Genetic Foundations Genetic Foundations of Development • DNA and the collaborative gene • DNA — deoxyribonucleic acid • Chromosomes — thread-like structures • Genes — units of hereditary information • Human Genome Project • 30,000 genes in humans

Genetic Foundations Cells, Chromosomes, Genes, and DNA Nucleus (center of cell) contains chromosomes and genes Gene: a segment of DNA (spiraled double chain) containing the hereditary code Chromosomes are threadlike structures composed of DNA molecules

Genetic Foundations The Collaborative Gene • Genes and chromosomes • Mitosis — cell nucleus duplicates • Meiosis — cell division forms gametes • Fertilization — egg and sperm form zygote • Genetic variability in the population • X and Y chromosomes determine sex

Genetic Foundations The Collaborative Gene • Genes and chromosomes • Identical and fraternal twins • Mutated gene • Genotype — all of one’s genetic makeup • Phenotype — observable characteristics

Genetic Foundations Genetic Principles • Dominant and recessive genes • Sex-linked genes • X-linked inheritance for males and females • Genetic imprinting • Imprinted gene dominates • Poly-genetically determined characteristics • Many genes interact to influence a trait

Genetic Foundations Brown hair B How brown-haired parents can have a blond-haired child: the gene for blond hair is recessive Blond hair b Father B b Mother B b B B B b B b b b

Genetic Foundations Genetic Principles • Chromosome abnormalities • Down syndrome • Sex-linked chromosome abnormalities • Klinefelter syndrome • Fragile X syndrome • Turner syndrome • XYY syndrome

KlinefelterSyndrome Males have an extra X chromosome Fragile X syndrome Abnormality in the X chromosome Turner syndrome Females missing an X chromosome XYY syndrome Males have an extra Y chromosome Genetic Foundations Sex-Linked Chromosome Abnormalities

Genetic Foundations Gene-Linked Abnormalities • PKU: phenylketonuria • Sickle-cell anemia • Cystic fibrosis • Diabetes • Hemophilia • Genetic disorders can sometimes be compensated for by other genes or events

Heredity, Environment, and Individual Differences Nature-Nurture Debate • Behavior Genetics • Studies influence of heredity and environment on individual differences • Studies use twins or adoptees • Monozygotic and dizygotic twins • Adoption study: examine behavior and psychological characteristics

Heredity, Environment, and Individual Differences Heredity-Environment Correlations • In infancy, environment mostly controlled by parents • As children age, their experiences extend more beyond the family’s influence • Shared environments are analyzed • Commonalities between children attributed to heredity-environment interaction

Heredity, Environment, and Individual Differences Heredity-Environment Correlations • Passive genotype-environment correlations • Evocative genotype-environment correlations • Active (niche-picking) genotype-environment correlations

Heredity, Environment, and Individual Differences Heredity-Environment Correlations • In infancy, environment mostly controlled by parents • As children age, their experiences extend more beyond the family’s influence • Shared environments are analyzed • Commonalities between children attributed to heredity-environment interaction

Heredity, Environment, and Individual Differences The Heredity-Environment and Epigenetic Views

Prenatal Development The Course of Prenatal Development • Germinal period: 2 weeks after conception • Embryonic period: 2 to 8 weeks after conception • Three layers: endodem, mesoderm, ectoderm • Umbilical cord connect to placenta • Organogenesis • Fetal period • From 2 months after conception to birth • Trimesters of pregnancy

Prenatal Development 0 - 4 weeks Less than 1/10th of inch long First trimester 8 weeks Less than 1 inch long 12 weeks 3 inches long, wt: 1 ounce 16 weeks 5.5 inches long, wt: 4 ounces Second trimester 20 weeks 10-12 inches, wt: ½ -1 lbs 24 weeks 11-14 inches, wt: 1-1½ lbs 28 weeks 14-17 inches, wt: 2½ -3 lbs Third trimester 32 weeks 16½ -18 inches, wt: 4-5 lbs 36-38 weeks 19 inches, wt: 6 lbs The three trimesters of prenatal development

Prenatal Development Prenatal Diagnostic Tests • Ultrasound sonography • Chorionic villi sampling: small sample of placenta taken • Amniocentesis: samples amniotic fluid • Maternal blood test

Prenatal Development The Brain • Neurons – 100 billion • Birth defects and neural tube • Neuronal migration occurs

Prenatal Development Hazards to Prenatal Development • Teratogen: agent causing birth defects • Severity of damage affected by • Dose • Genetic susceptibility • Time of exposure • Effects of prescription and nonprescription drugs

Prenatal Development Teratogens and Timing of Their Effects on Prenatal Development

Prenatal Development Hazards to Prenatal Development • Psychoactive drugs • Caffeine • Alcohol and fetal alcohol syndrome (FAS) • Nicotine’s link to SIDS, ADHD, low birth weight • Effect of father’s smoking • Cocaine, marijuana, and heroin • Methamphetamine • Environmental hazards and pollutants

Prenatal Development Hazards to Prenatal Development • Incompatible blood types of parents • Rh-positive and Rh-negative • Maternal diseases like German measles, syphilis, HIV and AIDS • Other prenatal factors • Nutrition, prenatal education and care • Maternal age and risks • Maternal emotional states and stress • Paternal factors • Environmental factors

Birth Prenatal Care • Prenatal programs • Education • Medical care • Social and nutritional services • Low birth weight and infant mortality rates • View of pregancy vary among cultures and ethnic groups

Birth The Birth Process • Stages of birth: occurs in three stages • Uterine contractions • Baby’s head moves through birth canal • Afterbirth when placenta, umbilical cord, and other membranes are detached and expelled • Baby must withstand stress of birth

Birth Strategies for Childbirth • Deciding what setting, who attends, and what technique will be used • Home delivery, birthing center, or hospital? • 99% of all U.S. births occur in hospitals • Home births more common outside U.S. • Doula as caregiver • Role of midwife, nurse, and physician

Birth Methods of Delivery • Medication with analgesics (epidural block, oxytocics, etc.) • Possible effects of drugs on fetus • Natural childbirth • Prepared childbirth and the Lamaze method • Cesarean sections for breech babies, other risks and benefits

Birth Methods of Delivery • Nonmedicated techniques • Waterbirth more in European countries • Massage reduces pain and anxiety • Acupuncture is standard in China • Hypnosis has some positive effects • Music therapy reduces stress, manages pain

Birth Assessing the Newborn • Apgar Scale: heart, reflexes, and color • Brazelton Neonatal Behavioral Assessment Scale (BNBAS) • A sensitive index of neurological competence • Four categories in global terms • Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS) • Analysis of behavior, neurological and stress responses, and regulatory capacities

Birth The Apgar Scale

Birth Low Birth Weight and Preterm • Low birth weight infants in U.S. and world • Weigh less than 5.5 lbs • Very low birth weight: less than 3 lbs • Preterm infants: 35 or fewer weeks after conception (about 12% of U.S. births) • Small-for-date infants: weigh less than they should • Ethnic variations characterize preterm birth • Causes and consequences

Birth Kangaroo Care and Massage Therapy • Kangaroo care • Holds infant to promote skin-to-skin contact between infant and caregiver • Can promote • Better breathing • Longer sleep periods • Weight gain • Less crying • Longer periods of alertness

Birth Tiffany Field’s Research on Massage Therapy • Massage therapy led to 47% greater weight gain for preterm infants • Also demonstrated benefits of massage for • Labor pain • Asthma • ADHD • Arthritis • Autistic children

Birth Weight Gain Comparison of Premature Infants Who Were Massaged and Not Massaged

Birth Bonding • Needs to occur shortly after birth • Early emotional attachments may create healthy interactions after leaving hospital • Rooming-in arrangements offered • Massages and tactile stimulation for premature infants affect development

Biological Beginnings